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Diffstat (limited to 'drivers/iommu/iova.c')
-rw-r--r--drivers/iommu/iova.c14
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index b6cf5f16123b..0af42fb93a49 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -121,8 +121,6 @@ int init_iova_flush_queue(struct iova_domain *iovad,
spin_lock_init(&fq->lock);
}
- smp_wmb();
-
iovad->fq = queue;
timer_setup(&iovad->fq_timer, fq_flush_timeout, 0);
@@ -633,10 +631,20 @@ void queue_iova(struct iova_domain *iovad,
unsigned long pfn, unsigned long pages,
unsigned long data)
{
- struct iova_fq *fq = raw_cpu_ptr(iovad->fq);
+ struct iova_fq *fq;
unsigned long flags;
unsigned idx;
+ /*
+ * Order against the IOMMU driver's pagetable update from unmapping
+ * @pte, to guarantee that iova_domain_flush() observes that if called
+ * from a different CPU before we release the lock below. Full barrier
+ * so it also pairs with iommu_dma_init_fq() to avoid seeing partially
+ * written fq state here.
+ */
+ smp_mb();
+
+ fq = raw_cpu_ptr(iovad->fq);
spin_lock_irqsave(&fq->lock, flags);
/*